1. Field of the Invention
This invention is related to single use cameras and to the use of pre-exposed film in cameras of this type in which a predetermined message can be included in photographs to be subsequently exposed in individual frames of the film. This invention is also related to the alignment of the pre-exposed sections of the film with the film frames to be subsequently exposed.
2. Description of the Prior Art
A typical user can incorporate multiple images into photographs by using pre-exposed film pre-loaded in a camera of the type in which the entire camera can returned for development without removing the film from the camera. A portion of the film used in these cameras has been pre-exposed so that a title or border, typically containing a separate image and/or text, will be part of each photograph. The remaining portion of each frame on this film is exposed in a single use type camera that includes an insert which prevents re-exposure of the previously exposed image. A camera of this type is shown in U.S. Pat. No. 5,853,795.
To pre-expose a stripe or border or portion of the film used in these cameras, an image is typically projected from a master image onto the film negative. The majority of each film frame remains unexposed and forms the area in which the main image will be formed on the composite photograph. U.S. Pat. No. 5,794,087 discloses an apparatus for pre-exposing a latent image on bulk film that is then loaded into a pre-loaded camera of a conventional type. Although the image on a continuous reel can be repetitively transferred to the bulk film, the bulk film must then be loaded into standard film cassettes or into a pre-loaded camera in a low light environment in which the remaining portions of the film strip are not exposed. This approach also employs a continuous border surrounding each frame, thus limiting the area available for exposing the principal image. The pre-exposed image must also be precisely aligned with the lens and the aperture frame in which the pre-exposed film is to be used, if the two exposures are to be properly aligned in the finished photographs.
The instant invention is intended to simplify, if not totally eliminate, the alignment problems that must be resolved for prior art multiple exposure photographs. The pre-exposed image of this invention is formed by a contact exposure method, as opposed to a employing a projected image which is more difficult to accurately locate. Furthermore, the film is pre-exposed and then loaded into a film canister in the same light tight enclosure, so there is no need to protect the larger unexposed portion of the film strip from inadvertent exposure. The pre-exposed film strip generated in accordance with this invention may also not require precise registration in the camera in which it is to be used, if the pre-exposed section is not a discrete single image, and it can be either pre-loaded into a single use type camera or it can be loaded into a camera by the user.
A photographic film strip in the form of a length of photographic film has a pre-exposed area and an unexposed area. The pre-exposed area is continuous and extends along one edge of the strip between ends of the strip. The unexposed area is also continuous and has a length suitable for making multiple single exposure frames with adjacent frames being separated by a frame line. Upon development of the film, an image formed by the pre-exposed section of each print will extend between opposite edges of prints formed by individual frames without the need to preregister the film in a camera. The pre-exposure comprises a contact exposure.
An apparatus for pre-exposing a first portion of a photographic film strip for subsequent use in a camera in which a remaining portion of the photographic film strip is to be exposed is also disclosed. The apparatus includes a light tight enclosure and a cylindrical drum located in the light tight enclosure. The apparatus also includes a master image disposed on a peripheral rim of the cylindrical drum. The master image has an opaque section and an image section. A light source is located on the interior of the cylindrical drum. An initially unexposed photographic film strip is held in registry with the master image, with the first portion in registry with the image section of the master image and with the remaining portion of the photographic film strip in registry with at least part of the opaque section of the master image. The light source can be activated to expose the first portion of the photographic film strip, between its opposite ends, in a single flash.
One process for fabricating a photographic film strip having a pre-exposed first section and an unexposed second section starts with the step of fabricating a master film strip by successively exposing a portion adjacent one edge of the film strip to a first image through a frame aperture having one area with a width greater than the width of a frame to be exposed in the camera. A pre-exposed first portion therefore has a length greater than the width of the frame. The master film strip is then positioned in contact with the photograph film strip with an emulsion side of each film strip contacting an emulsion side of the other film strip. Only the portion of the photographic film strip in contact with the pre-exposed first portion of the master film strip along one edge is exposed so that the pre-exposed first section will extend laterally beyond opposite edges of each frame to be formed on the photograph film strip. Then it will not be necessary to precisely position the photographic film strip when it is loaded into the camera.
A partially exposed photographic film of this type can be used in either a preassembled cameraxe2x80x94film package and in a camera that is loaded by the user. One such camera includes a shiftable partition located adjacent one edge of a film frame aperture. The shiftable partition is movable between a first and a second position. When the shiftable partition is in the first position, the film frame aperture is completely open. When the shiftable partition is in the second position, a portion of the film frame aperture along the one edge is blocked to prevent exposure of film behind the shiftable partition. This camera can be used with a standard unexposed film strip when the shiftable partition is in the first position. The same camera can be used with a partially pre-exposed film strip when the shiftable partition is in the second position.